JP2009156127A - Intake manifold device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake manifold device with a passage length change-over part to be smoothly operated for further improving the air tightness of intake air. <P>SOLUTION: In an intake manifold 14, an intake passage 16 is provided in which intake air is distributed to be supplied to an engine 22. On the midway of the intake passage 16, the passage length change-over part 18 is provided which has a plurality of valves 40 for freely changing over the length of the passage. At both ends of each of the valves 40, elastic-material seal members 48a, 48b are mounted which abut on first and second seat parts 36, 42 of the intake passage 16 with the turning displacement of the valve 40, respectively, to communicate the valve 40 with the intake passage 16. Thus, the seal members 48a, 48b hold air tightness in the intake passage 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intake manifold device for an internal combustion engine, and more particularly to an intake manifold device for an internal combustion engine having a passage length switching portion capable of switching the length of an intake passage through which intake air flows.

  2. Description of the Related Art Conventionally, in a multi-cylinder engine such as an automobile, an intake manifold is provided between an intake port of a cylinder head and a throttle valve that adjusts an intake air amount, and the intake air sucked into the intake manifold is divided to each intake air. Distribution to ports.

  In recent years, with the increase in engine output, intake air for an internal combustion engine having a passage length switching portion that shortens the intake passage of the intake manifold at high speed or high load operation and lengthens the intake passage of the intake manifold at low speed or low load operation. A manifold device is known, and the present applicant has proposed an intake manifold device for an internal combustion engine having a passage length switching portion that can sufficiently ensure airtightness between the intake manifold and the joint (see Patent Document 1). . In this passage length switching unit, a seal body is provided between the intake manifold and the holding body inserted through the intake manifold, so that the airtightness between the intake manifold and the holding body can be maintained.

JP 2003-83072 A

  The present invention has been made in connection with the above-mentioned proposal, and reduces the operating resistance when switching the passage length of the intake passage by means of the passage length switching portion, thereby enabling smooth operation and further improving the airtightness of the intake air. An object of the present invention is to provide an intake manifold device for an internal combustion engine that can be improved.

In order to achieve the above object, the present invention provides an intake manifold having an intake passage that is independently connected to each cylinder of a main body constituting an internal combustion engine and communicates with a chamber into which intake air is introduced from a throttle device. An intake manifold device for an internal combustion engine, provided with a passage length switching unit that is provided inside the intake manifold facing the intake passage and switches a passage length of the intake passage according to an operating state of the internal combustion engine.
The passage length switching portion is provided between a first passage portion constituting the intake passage and connected to the chamber, and a second passage portion constituting the intake passage and connected to the main body portion, A cylindrical switching valve supported rotatably with respect to the intake manifold;
A seal member formed of an elastic material and provided at an end of the switching valve facing the first and second passage portions;
With
The seal member is formed of an elastic material, and has a contact portion that makes line contact with a sheet portion provided at an end of the first and second passage portions.

  According to the present invention, a sealing member made of an elastic material is attached to the end of the switching valve constituting the passage length switching portion, and the sealing member is formed in the first and second passage portions constituting the intake passage. There is provided a contact portion that can contact the seat portion. Then, the sealing member is brought into contact with and brought into close contact with the seat portion via the contact portion, so that the airtightness when the first passage portion and the second passage portion communicate with each other under the rotating action of the switching valve is suitably maintained. In addition, since the contact portion is in line contact with the seat portion, the operating resistance at the time of switching the communication state between the first passage portion and the second passage portion by rotating the switching valve is reduced. The switching operation by the passage length switching unit can be performed smoothly.

  Further, the contact portion is a step portion facing the seat portion and having a diameter reduced stepwise toward the seat portion, so that the step portion is brought into contact with the seat portions of the first and second passage portions. The airtightness when the first and second passage portions communicate with each other through the switching valve can be suitably maintained, and the sliding resistance when the switching valve rotates can be reduced.

  Further, the contact portion is a plurality of protrusions extending along the axial direction of the seal member and spaced apart from each other by a predetermined distance, so that the end portions of the protrusions are seat portions of the first and second passage portions. The airtightness when the first and second passage portions communicate with each other by the switching valve can be suitably maintained, and the sliding resistance when the switching valve rotates is reduced. Can do.

  According to the present invention, the following effects can be obtained.

  That is, a sealing member made of an elastic material is attached to the end of the switching valve constituting the passage length switching portion, and the seat portion formed in the first and second passage portions constituting the intake passage is attached to the sealing member. By providing a contact portion that can freely contact the seal member, the seal member can be brought into close contact with the seat portion via the contact portion, and when the first passage portion and the second passage portion communicate with each other via the switching valve. Since the airtightness can be suitably maintained and the contact portion is in line contact with the seat portion, the operating resistance when switching the communication state between the first passage portion and the second passage portion can be reduced. Thus, the switching operation by the passage length switching unit can be performed smoothly.

  A preferred embodiment of an intake manifold device for an internal combustion engine according to the present invention will be described in detail below with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates an intake manifold device for an internal combustion engine according to the first embodiment of the present invention. Here, an intake manifold device applied to a multi-cylinder engine having a plurality of cylinders will be described.

  An intake manifold device 10 for an internal combustion engine (hereinafter referred to as an intake manifold device 10) is provided in, for example, a 4-cylinder engine having four cylinder chambers mounted on a vehicle or the like.

  As shown in FIGS. 1 and 3, the intake manifold device 10 includes an intake manifold 14 having a plurality of branch pipes 12, and an intake passage 16 that is inserted into the branch pipe 12 of the intake manifold 14 and through which intake air flows. A path length switching unit 18 that switches the length of the path, and a drive unit (not shown) for rotationally displacing the path length switching unit 18.

  The intake manifold 14 is integrally formed, for example, by welding or bonding a plurality of divided bodies obtained by injection molding of a resin material. The intake manifold 14 includes a chamber 20 that temporarily stores air sucked through a throttle valve of a throttle device (not shown), and an intake passage 16 that is connected to the chamber 20 and guides the air from the chamber 20 to the engine 22. And have. The intake manifold 14 includes a mounting flange 26 connected to the cylinder head 24 of the engine 22, and the mounting flange 26 is coupled to the cylinder head 24 through an end face formed in a planar shape.

  The chamber 20 has a substantially L-shaped cross section and extends along the longitudinal direction of the intake manifold 14. The chamber 20 is disposed on the engine 22 side and is connected to one end of the intake passage 16. And a second space portion 30 that extends in a direction away from the engine 22 with respect to the lower portion of the space portion 28 and to which a part of the intake passage 16 is connected.

  The intake passage 16 is provided inside the branch pipe 12 and is formed in a tubular shape having a substantially constant diameter, and is provided along the inside of the branch pipe 12 spaced apart from each other by a predetermined distance. That is, the plurality of intake passages 16 are arranged substantially in parallel at a predetermined interval from each other.

  The intake passage 16 is disposed on the lower side of the first space portion 28 and the second space portion 30 constituting the chamber 20 along the longitudinal direction of the intake manifold 14, and moves upward along the outer wall surface of the intake manifold 14. And a connecting portion (second passage portion) 34 for connecting the upper portion of the second space 30 and the engine 22 to each other.

  The bending portion 32 has one end connected to the lower portion of the first space portion 28 and the other end connected to the lower portion of the second space portion 30, and the first space portion 28, the second space portion 30, and the like. Is in communication. In other words, the bending portion 32 connects the lower portions of the first space portion 28 and the second space portion 30 by bending.

  In addition, a first sheet portion 36 is formed at the other end of the curved portion 32 so as to protrude from the inner wall surface of the second space portion 30 constituting the chamber 20 and to expand radially outward. Is done. The first seat portion 36 is formed in an annular shape having a predetermined diameter, and one end portion of the valve 40 constituting the passage length switching portion 18 contacts.

  One end portion of the connection portion 34 is connected to the upper portion of the second space portion 30 and is disposed coaxially with the other end portion of the bending portion 32 facing the second space portion 30, and the other end portion is the first space portion. 2 Curved from the space 30 toward the engine 22 side and disposed above the chamber 20. The other end of the connecting portion 34 is connected to the cylinder head 24 constituting the engine 22 via the mounting flange 26, and the connecting portion 34 and the cylinder head 24 communicate with each other.

  In addition, a second sheet portion 42 is formed at one end portion of the connecting portion 34 so as to protrude radially outward with respect to the inner wall surface of the second space portion 30 like the other end portion of the bending portion 32. Is done. The second seat portion 42 is formed in an annular shape having a predetermined diameter, and the other end portion of the valve 40 constituting the passage length switching portion 18 contacts.

  That is, the curved portion 32 and the connecting portion 34 constituting the intake passage 16 communicate with each other through the second space portion 30 constituting the chamber 20, and one end portion of the intake passage 16 is connected to the first portion of the chamber 20 via the curved portion 32. The other end portion of the intake passage 16 is connected to the cylinder head 24 of the engine 22 via the connection portion 34.

  As shown in FIGS. 1 to 3, the passage length switching portion 18 is provided between the curved portion 32 of the intake passage 16 and the connection portion 34 inside the chamber 20, and is supported by the intake manifold 14. 44 and a plurality of valves 40 that are held by the shaft 44 and switch the flow state of the intake passage 16.

  The shaft 44 is formed in an axial shape having a constant diameter, passes through the plurality of intake passages 16 so as to be substantially orthogonal to the axis of the intake passage 16, and includes a connection portion 34 constituting the intake passage 16 and It arrange | positions so that it may be on the axis line of the bending part 32. FIG.

  The shaft 44 is rotatably held with respect to the intake manifold 14, and a driving unit (not shown) is connected to the end of the shaft 44. The shaft 44 is rotationally displaced by a predetermined angle (for example, 90 °) under the drive action of the drive unit. The drive unit is composed of, for example, a stepping motor that is driven to rotate under energization, and the rotation angle of the drive unit is set based on a control signal input from a controller (not shown) to the drive unit. Controlled by angle.

  The valve 40 is disposed between the curved portion 32 and the connection portion 34 in the intake passage 16 according to the number of the intake passages 16 (for example, four), and is formed in a substantially cylindrical shape. It consists of a pair of seal members 48a and 48b attached to both ends of the body 46.

  The body 46 is formed with a through hole 50 penetrating along the axial direction, and the through hole 50 is formed with a constant diameter substantially equal to the inner peripheral diameter of the intake passage 16.

  A shaft 44 is inserted through the central portion of the body 46 in a direction perpendicular to the through hole 50, and a plurality of valves 40 are arranged in parallel at a predetermined interval via the shaft 44 (see FIG. 2). ). The plurality of valves 40 are rotatably supported in the chamber 20 facing the connecting portion 34 and the curved portion 32 constituting the intake passage 16 via the shaft 44.

  On the other hand, at both ends of the body 46, a flange 52 slightly enlarged in the radial outward direction and a mounting end 54 that protrudes in an annular shape with respect to the flange 52 and to which the seal members 48a and 48b are mounted are formed. (See FIG. 3).

  The seal members 48 a and 48 b are formed in a substantially cylindrical shape from an elastic material (for example, rubber) having a constant thickness, and a holding portion 56 provided on one end side is attached to the attachment end 54 of the body 46.

  The holding portion 56 has a substantially constant diameter, and an end thereof abuts on the flange portion 52 of the body, and a part of an inner peripheral surface abuts on an outer peripheral surface of the mounting end 54, for example, the holding portion 56. It is fixed by an adhesive or the like applied to That is, the holding portion 56 is attached to the body 46 so as to cover the attachment end 54, and the outer peripheral surface of the flange portion 52 and the outer peripheral surface of the holding portion 56 are substantially the same diameter in the state of being attached to the body 46. It becomes.

  Further, the seal members 48a and 48b are gradually reduced in diameter in a circular arc shape from the holding portion 56 formed at one end portion toward the other end side, and are separated from the holding portion 56 at the other end portion. It has a seating portion (contact portion) 58 that has a diameter reduced stepwise in the direction. The seat portion 58 is formed so as to be able to contact the first and second seat portions 36 and 42 of the intake passage 16, and the end portions facing the first and second seat portions 36 and 42 are opened. The body 46 communicates with the through hole 50.

  The seating part 58 is adjacent to the first step part 60 formed closest to the holding part 56, the second step part 62 further reduced in diameter adjacent to the first step part 60, and the second step part 62. The projection 64 is further reduced in diameter and projected.

  The first step portion 60 has a diameter reduced with respect to the holding portion 56 and extends along the axis of the seal members 48a and 48b, and is folded radially inward at a right angle to the circumference portion. A corner portion (contact portion) 60a formed in a substantially L-shaped cross section composed of a bent portion and having the circumferential portion and the bent portion joined to each other is formed with respect to the first and second sheet portions 36 and 42. Abut.

  The second step portion 62 has a reduced diameter with respect to the circumferential portion of the first step portion 60, and the circumferential portion extending along the axis of the seal members 48a and 48b as in the first step portion 60; A corner portion 62a formed in a substantially L-shaped cross section consisting of a bent portion bent in a radial inward direction at a right angle to the circumferential portion, and a junction between the circumferential portion and the bent portion, Similar to the first step portion 60, the first and second sheet portions 36 and 42 abut against each other.

  The protruding portion 64 extends from the bent portion constituting the second step portion 62 with a predetermined length along the axial direction of the seal members 48a, 48b, and the end portions thereof are the first and second sheet portions 36, 42. Abut against.

  That is, in the seating portion 58, the corner portion 60 a in the first step portion 60, the corner portion 60 b in the second step portion 62, and the end portion of the protruding portion 64 abut against the first and second seat portions 36 and 42. To keep it airtight. Further, the end portions of the corner portions 60 a and 60 b and the protruding portion 64 are in line contact with the first and second sheet portions 36 and 42.

  Furthermore, as for the length of the protrusion part 64 along the axial direction of the sealing members 48a and 48b, the first and second step parts 60 and 62, for example, the protrusion part 64 is set to be the longest, and the first step part 60 is The shortest is set. That is, the first step portion 60, the second step portion 62, and the protruding portion 64 are set so as to be gradually longer (see FIG. 3).

  In addition, the protrusion part 64, the 1st and 2nd step part 60, 62 are not limited to when the length along each axial direction differs as mentioned above, For example, the said protrusion part 64, the 1st, The lengths of the first and second step portions 60 and 62 may be set to be the same.

  That is, the seating portion 58 is formed so as to gradually taper in a direction away from the holding portion 56 so as to correspond to the shape of the first and second seat portions 36 and 42.

  Further, the length along the axial direction of the valve 40 including the body 46 and the seal members 48a and 48b is set to be equal to the separation distance between the first seat portion 36 and the second seat portion 42 constituting the intake passage 16. In addition, the outer peripheral diameter of the valve 40 is set smaller than the separation distance.

  Then, the valve 40 rotates together with the shaft 44, and one seal member 48a provided at one end thereof abuts on the first seat portion 36 of the connection portion 34 and the other seal member provided at the other end portion. When 48 b abuts on the second seat portion 42 of the bending portion 32, the axis of the valve 40 is coaxial with the axes of the connecting portion 34 and the bending portion 32. Thus, a long pipe intake passage L is formed in which the curved portion 32 and the connection portion 34 constituting the intake passage 16 communicate with each other through the through hole 50 of the valve 40 (see FIG. 1).

  In this case, the sealing member 48a attached to one end of the valve 40 is sealed by coming into contact with the first seat portion 36, so that the intake air leaks between the valve 40 and the first seat portion 36. Is prevented. Similarly, the seal member 48b attached to the other end portion of the valve 40 is sealed by coming into contact with the second seat portion 42, and suction from between the valve 40 and the second seat portion 42 is performed. Air leakage is prevented.

  On the other hand, under the rotational action of the shaft 44, the valve 40 is rotationally displaced so that one seal member 48a faces the first space 28 and the other seal member 48b faces the second space 30. As a result, the connecting state between the bending portion 32 and the connecting portion 34 constituting the intake passage 16 by the valve 40 is released. As a result, as shown in FIG. 4, the first and second seat portions 36 and 42 are spaced apart from the outer peripheral surface of the valve 40 by a predetermined distance, and a gap is provided therebetween.

  The intake air introduced into the first and second space portions 28 and 30 constituting the chamber 20 passes through the gap between the first and second seat portions 36 and 42 and the valve 40 to the connection portion 34 of the intake passage 16. And circulate. Thus, a short pipe intake passage S is formed in which the intake air introduced into the chamber 20 flows directly to the connection portion 34 of the intake passage 16. The length of the short pipe intake passage S is shorter than the length of the long pipe intake passage L including the curved portion 32 formed in a curved shape along the outer wall surface of the intake manifold 14. Note that the intake air introduced into the first space portion 28 of the chamber 20 also flows to the connection portion 34 side through the bending portion 32.

  That is, when the engine 22 having the intake manifold device 10 is operated at a high speed or a high load, the short pipe intake is performed so that the passage length of the intake passage 16 is shortened under the rotating action of the valve 40 constituting the passage length switching unit 18. Switching to the passage S and supplying the intake air to the cylinder head 24 through the connecting portion 34, and at the time of low speed or low load operation of the engine 22, the valve 40 is rotated to turn the through hole 50, the curved portion 32, and the connecting portion. By communicating 34, the intake air is supplied to the cylinder head 24 through the long pipe intake passage L having a long passage length including the curved portion 32, the connection portion 34, and the through hole 50 of the valve 40.

  The intake manifold device 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation, action, and effect thereof will be described.

  For example, when the engine 22 is operating at a low speed or under a low load, the shaft 44 is urged under the elastic action of a spring (not shown), and the valve 40 is rotated counterclockwise (in the direction of arrow A) as the shaft 44 is displaced. The curved portion 32 and the connecting portion 34 that rotate to constitute the intake passage 16 and the valve 40 are arranged so as to be coaxial. As a result, the seal members 48a and 48b attached to both ends of the valve 40 are in contact with the first and second seat portions 36 and 42 provided at the end portions of the intake passage 16, respectively.

  Specifically, the end portions of the projecting portion 64 of the seal members 48a and 48b and the corner portions 60a and 62a of the first and second step portions 60 and 62 respectively contact the inner wall surfaces of the first and second seat portions 36 and 42. The valve 40, to which the seal members 48a and 48b are mounted, and the curved portion 32 and the connection portion 34 of the intake passage 16 are maintained in close contact with each other.

  The curved portion 32 of the intake passage 16 and the connecting portion 34 are connected and communicated by the valve 40 constituting the passage length switching portion 18, and the chamber 20 is communicated with the engine 22 through the long pipe intake passage L. Become. Thereby, the supply of the intake air from the chamber 20 to the engine 22 is performed from the first space portion 28 of the chamber 20 through the long pipe intake passage L constituted by the curved portion 32 and the connecting portion 34.

  In this case, since the intake air is supplied from the chamber 20 to the engine 22 through the curved portion 32, the valve 40, and the connection portion 34 constituting the long pipe intake passage L, the intake air is passed through the long pipe intake passage L having a long passage length. The flow rate of intake air per unit time taken into the engine 22 is reduced.

  In addition, leakage of intake air from between the intake passage 16 and the valve 40 is prevented by the pair of seal members 48 a and 48 b, and intake air is reliably supplied from the chamber 20 to the engine 22.

  On the other hand, when the engine 22 is operating at a high speed or a high load, a control signal based on the engine speed or the like is output from a controller (not shown) to the drive unit, and the drive unit is an elastic force of a spring (not shown). As a result, the valve 40 is rotated clockwise (in the direction of arrow B) by a predetermined angle through the shaft 44 by being rotationally driven in the opposite direction.

  As shown in FIG. 4, the axis of the valve 40 is substantially perpendicular to the axes of the curved portion 32 and the connecting portion 34 constituting the intake passage 16, and one seal member 48 a is the first space portion of the chamber 20. 28, the other sealing member 48 b faces the second space 30 of the chamber 20. As a result, the communication between the curved portion 32 and the connecting portion 34 through the valve 40 is released, and the first and second space portions 28 and 30 pass through the gap between the second seat portion 42 and the outer peripheral surface of the valve 40. Intake air flows to the connecting portion 34. That is, a short pipe intake passage S that is directly introduced from the first and second space portions 28 and 30 to the connection portion 34 of the intake passage 16 is configured, and intake air is supplied to the engine 22 through the short pipe intake passage S. Is done. As a result, the intake air is supplied from the chamber 20 to the engine 22 through the connection portion 34 of the intake passage 16 in a short time and in a large volume.

  Thus, the flow rate and the inflow time of the intake air sucked into the engine 22 are suitably controlled under the switching action of the passage length switching unit 18 according to the operating state of the engine 22, and accordingly, the engine 22 The output can be improved.

  As described above, in the first embodiment, the sealing members 48a and 48b made of an elastic material such as rubber are respectively attached to both ends of the valve 40 constituting the passage length switching unit 18, and the sealing members 48a, 48a, 48b is provided with a seating portion 58 that can come into contact with the first and second seat portions 36, 42 facing the intake passage 16.

  Thus, by forming the sealing members 48a, 48b from an elastic material such as rubber, the first and second seat portions 36, 36 of the intake passage 16 are surely and preferably secured by the elastic force of the sealing members 48a, 48b. 42 can be closely attached. As a result, leakage of the intake air flowing through the valve 40 to the cylinder head 24 can be prevented, and the intake air can be supplied at a desired flow rate.

  Further, when the valve 40 is rotated in order to switch the passage length of the intake passage 16, only the seating portions 58 of the seal members 48a and 48b are displaced while being in sliding contact with the first and second seat portions 36 and 42. Compared with the case where the end surfaces of the sealing members 48a and 48b are sealed against the first and second seat portions 36 and 42 as a whole, the sliding resistance is reduced, so that the valve 40 is rotated. It is possible to reduce the operating torque when moving. As a result, the switching operation of the valve 40 can be performed smoothly. In addition, since the corner portions 60a and 60b and the end portions of the projecting portions 64 constituting the seal members 48a and 48b are in line contact with the first and second sheet portions 36 and 42, the seal members are connected to the first and second seal portions 48a and 48b. Compared with the case where the second sheet portions 36 and 42 are in surface contact, the sliding resistance can be reduced.

  Further, since the load on the drive unit that drives the passage length switching unit 18 including the valve 40 is reduced by reducing the operating torque when the valve 40 rotates, it is possible to reduce the size of the drive unit. It becomes.

  Further, by reducing the operating resistance when the seal members 48a and 48b slide along the first and second sheet portions 36 and 42, the seal members 48a and 48b are made of an elastic material such as rubber having a large frictional resistance. Even if it is formed, the operability of the valve 40 does not decrease, which is preferable. In other words, even when an elastic material such as rubber having a large sealing force is applied to the seal members 48a and 48b, the passage length switching unit 18 including the valve 40 can be operated smoothly and the passage length can be switched. It becomes.

  Furthermore, by forming the sealing members 48a and 48b from an elastic material such as rubber, the first and second seat portions 36 and 42 of the intake passage 16 are surely and preferably secured by the elastic force of the sealing members 48a and 48b. Can be adhered to. As a result, leakage of the intake air flowing to the cylinder head 24 through the valve 40 can be prevented, and the intake air can be supplied to the engine 22 at a desired flow rate.

  Next, an intake manifold device 100 according to a second embodiment is shown in FIGS. The same components as those of the intake manifold device 10 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the intake manifold device 100 according to the second embodiment, the seating portions 106 of the seal members 104a and 104b constituting the passage length switching portion 102 extend toward the first and second seat portions 36 and 42. It is different from the passage length switching unit 18 of the intake manifold device 10 according to the first embodiment in that the first to third ribs (projections) 108a to 108c are configured.

  Seal members 104a and 104b attached to both ends of the valve 110 are formed in a tapered shape so as to gradually reduce the diameter of the holding portion 56 attached to the attachment end 54 of the body 46 and the holding portion 56. And the first to third ribs 108a to 108c erected so as to face the first and second sheet portions 36 and 42 with respect to the tapered portion 112.

  The first to third ribs 108a to 108c extend in a direction away from the holding portion 56, and are provided in the tapered portion 112 inclined by a predetermined angle with respect to the axis of the seal members 104a and 104b. They are arranged in parallel and spaced apart from each other by a predetermined distance.

  The first rib 108a is disposed closest to the holding portion 56, the third rib 108c is disposed at the tip of the taper portion 112 farthest from the holding portion 56, and the first rib 108a and the third rib 108c The second rib 108b is disposed between the two. The first to third ribs 108 a to 108 c are in line contact with the first and second sheet portions 36 and 42.

  Further, the lengths of the first to third ribs 108a to 108c are set so as to be longer in the order of the first rib 108a, the second rib 108b, and the third rib 108c, with the portion standing on the tapered portion 112 as a base point. Is done. The first to third ribs 108a to 108c are not limited to the case where they are set to different lengths as described above, and all the first to third ribs 108a to 108c have the same length. You may make it set.

  During low-speed or low-load operation of the engine 22, the valve 110 is disposed coaxially with the curved portion 32 and the connecting portion 34 constituting the intake passage 16, and the curved portion 32 and the connecting portion 34 are connected by the valve 110. Then, when communicating, the end portions of the first to third ribs 108a to 108c abut against the first and second sheet portions 36 and 42, respectively (see FIGS. 5 and 6). As a result, the leakage of the intake air flowing through the intake passage 16 to the outside is prevented by the seal members 104a and 104b, and the air tightness in the intake passage 16 is maintained.

  On the other hand, when the valve 110 is rotated clockwise (in the direction of arrow B) by a predetermined angle during high speed or high load operation of the engine 22 and the passage length of the intake passage 16 is switched, the valve 110 is under the rotating action. The first to third ribs 108a to 108c constituting the sealing members 104a and 104b are slidably displaced with respect to the first and second sheet portions 36 and 42. One seal member 104b faces the first space portion 28 of the chamber 20, and the other seal member 104a faces the second space portion 30 of the chamber 20, and the communication between the curved portion 32 and the connection portion 34 is released. Thus, a short pipe intake passage S that is directly introduced from the first and second space portions 28 and 30 to the connection portion 34 of the intake passage 16 is configured.

  In this case, since the sealing members 104a and 104b are merely in contact with the first and second sheet portions 36 and 42, the end portions of the first to third ribs 108a to 108c are in contact with each other. The sliding resistance when the valve 110 is rotationally displaced while sliding the three ribs 108a to 108c is small, and the operating torque when the valve 110 is rotated can be reduced. Therefore, the switching operation of the valve 110 can be performed smoothly.

  Further, since the seal member is formed of an elastic material such as rubber, the seal members 104a and 104b are surely and suitably used with respect to the first and second seat portions 36 and 42 of the intake passage 16 under the elastic action. It is possible to prevent leakage of intake air supplied to the engine 22 through the valve 110 that is in close contact with the valve.

  Further, the third rib 108c disposed at the most distal end of the valve 110 is formed to have the longest length so that the seal members 104a and 104b can be moved together with the valve 110 while being in sliding contact with the first and second seat portions 36 and 42. When rotating, the third rib 108c pressed by the first and second sheet portions 36, 42 can be flexed suitably. As a result, the sliding resistance of the seal members 104a and 104b can be further reduced. On the other hand, by providing the first rib 108a on the holding portion 56 side and setting the length thereof to the shortest, the rigidity in the vicinity of the holding portion 56 can be maintained. Therefore, excessive deformation when the seal members 104a and 104b rotate while contacting the first and second sheet portions 36 and 42 can be suppressed.

  The intake manifold device for an internal combustion engine according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

1 is an overall longitudinal sectional view of an intake manifold device for an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is an external perspective view of a passage length switching unit constituting the intake manifold device for an internal combustion engine shown in FIG. 1. FIG. 2 is an enlarged cross-sectional view of the vicinity of a seal member that constitutes the passage length switching unit of FIG. 1. FIG. 3 is a longitudinal sectional view showing a state where an intake passage length is switched in the intake manifold device for an internal combustion engine of FIG. 2. It is a whole longitudinal cross-sectional view of the intake manifold apparatus for internal combustion engines which concerns on the 2nd Embodiment of this invention. FIG. 6 is an enlarged cross-sectional view of the vicinity of a seal member constituting the passage length switching unit of FIG. 5. FIG. 6 is a longitudinal sectional view showing a state in which the intake passage length is switched in the intake manifold device for the internal combustion engine of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100 ... Intake manifold apparatus 12 ... Branch pipe 14 ... Intake manifold 16 ... Intake passage 18, 102 ... Passage length switching part 20 ... Chamber 22 ... Engine 28 ... 1st space part 30 ... 2nd space part 32 ... Curve part 34 ... Connection part 36 ... First seat part 40, 110 ... Valve 42 ... Second seat part 48a, 48b, 104a, 104b ... Seal member 56 ... Holding part 58, 106 ... Seating part 60 ... First step part 62 ... Second Stepped portion 64 ... Protruding portion 108a to 108c ... First to third ribs

Claims (3)

An intake manifold that is independently connected to each cylinder of the main body constituting the internal combustion engine and has an intake passage communicating with a chamber into which intake air is introduced from a throttle device, and provided inside the intake manifold facing the intake passage An intake manifold device for an internal combustion engine comprising a passage length switching unit that switches a passage length of the intake passage in accordance with an operation state of the internal combustion engine,
The passage length switching portion is provided between a first passage portion constituting the intake passage and connected to the chamber, and a second passage portion constituting the intake passage and connected to the main body portion, A cylindrical switching valve supported rotatably with respect to the intake manifold;
A seal member formed of an elastic material and provided at an end of the switching valve facing the first and second passage portions;
With
The intake manifold device for an internal combustion engine, wherein the seal member is made of an elastic material and has a contact portion that makes line contact with a seat portion provided at an end portion of the first and second passage portions. The apparatus of claim 1.
The intake manifold device for an internal combustion engine, wherein the contact portion is a step portion facing the seat portion and having a diameter gradually reduced toward the seat portion. The apparatus of claim 1.
The intake manifold device for an internal combustion engine, wherein the contact portion includes a plurality of ribs extending along the axial direction of the seal member and spaced apart from each other by a predetermined distance.

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